The invention relates to an installation for machining work pieces with at least one machine tool which has a machine bed, a frame joined to the machine bed, a work spindle. A work spindle motion unit is disposed on the frame for moving the work spindle on a plane spanned by a vertical y direction. The work spindle is designed for holding a tool which extends perpendicular to the plane in a z direction. A working area is arranged on the machine bed before the work spindle in the z direction. A work piece holding means includes chucking devices for a work niece is arranged in the working area. At least one supply and take-down equipment is also provided.
In machine tools of the generic type known from EP 0 742 072 B1 (corresponding to U.S. Pat. No. 5,662,568 A) and EP 0 916 446 A1 (corresponding to U.S. Ser. No. 09/161 891) now U.S. Pat. No.6,328,575, the supply of work pieces for machining takes place in a way not described in detail. Customarily, the supply takes place laterally or from above into the working area.
DE 43 24 575 A1 (corresponding to U.S. Pat. No. 5,321,874) teaches to link successive machine tools to one another in such a way that a conveyor path is disposed above the machine tools and above the work holding fixtures that are in front thereof; horizontal carriages are displaceable on the conveyor path, having vertically movable holder beams, each bottom end of which being provided with work piece-transfer means in the form of grippers, which place the work pieces from above on the stationary work holding fixtures that belong to the machine tool, and lift them off upwards after working. The space requirements of such a design are extraordinary.
AT-PS 288 112 teaches an installation for machining work pieces that comprises several successive machine tools. A carriage is disposed for displacement on rails that are disposed on the floor in front of the machine tools. The carriage has forks in the way of a fork lift, by means of which to convey palletized work pieces from a supply rack to the respective machine tool. The pallets are inserted laterally into the working area of the machine tool, after which they are deposited vertically. This design too is rather complicated constructionally; it requires a lot of space and is accompanied with rather time-consuming supply and take-down jobs.
DE 195 16 849 C2 (corresponding to U.S. Pat. No. 6,135,696) teaches to interlink side-by-side machine tools so that work pieces are supplied from below to the machine tools. This offers the possibility of compact structure with reduced moving masses and short supply and take-down times, however, chips and cooling lubricants will drop from the machining place towards the supply and take-down equipment, the protection of which from cooling lubricants and chips not being possible or implying vast constructional requirements. Complicated motions of the work piece grippers of the supply and take-down equipment are necessary to reach the work holding fixtures of the machine tool.
It is an object of the invention to embody an installation of the generic type such that supply and take-down jobs are possible without costly constructional implementation and at reduced supply and take-down times, accompanied with high operational safety.
This object is attained by the supply and take-down equipment being arranged before the machine tool, in the z direction, before the side of the working area that faces away from the work spindle. Disposed before the machine tool is a conveyor path which runs substantially in the x direction and on which the supply and take-down equipment is displaceably supported. The supply and take-down equipment has at least a work piece transfer means. The work piece transfer means and/or the work piece holding means is displaceable in the z direction for transfer of a work piece from the work piece transfer means to the work piece holding means and vice versa. The measures according to the invention render the installation according to the invention very compact, meaning a reduction in moving masses and in the supply and take-down motions of the work piece transfer means. This arrangement ensures that only very few cooling lubricants and chips will move from the working area to the supply and take-down equipment. Transfer from the supply and take-down equipment to the work holding means of the machine tool and vice versa takes place exclusively by horizontal motions of the work holding means and/or the work transfer means, both being preferable equiaxed.
Embodiments according to the claims lead to further simplification of the supply and take-down equipment, highly simply designs of the z-displacement means, measures used for interlinking several machine tools, favorable adaption to differing work pieces, enabling a work to be seized and released rapidly, promoting the reduction of supply and take-down times.
In keeping with a further embodiment, a first work piece transfer means serves for holding a work that has been machined by the machine tool, while another work piece transfer means serves for feeding a work that is to be machined, which further reduces supply and takedown times.
In another embodiment, a work piece can be chucked in successive machine tools in positions that are twisted one relative to the other. Furthermore, a work piece can be rotated, for instance after machining, so that chips and/or coolant are removed.
In further embodiments the side of the machine tools, serves for rapid conveyance of the work piece from the place of transfer to the place of machining and possibly for handling at the place of machining.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which preferred embodiments of the invention are illustrated.